[lld] [ELF] delete peek2 in Lexer (PR #99790)

[Hongyu Chen via llvm-commits]

https://github.com/yugier created https://github.com/llvm/llvm-project/pull/99790

Thanks to Fangrui's change
https://github.com/llvm/llvm-project/commit/28045ceab08d41a8a42d93ebc445e8fe906f884c
so peek2 can be elimnated easily.

>From 8258fdda015056554d34fbb1875be33e4a2342c2 Mon Sep 17 00:00:00 2001
From: Hongyu Chen <hongyuchy at google.com>
Date: Sat, 20 Jul 2024 23:14:58 +0000
Subject: [PATCH 1/2] [ELF] delete peek2 in Lexer

Thanks to Fangrui's change
https://github.com/llvm/llvm-project/commit/28045ceab08d41a8a42d93ebc445e8fe906f884c
so peek2 can be elimnated easily.
---
 lld/ELF/ScriptLexer.cpp  |  9 ---------
 lld/ELF/ScriptLexer.h    |  1 -
 lld/ELF/ScriptParser.cpp | 26 ++++++++++++++------------
 3 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/lld/ELF/ScriptLexer.cpp b/lld/ELF/ScriptLexer.cpp
index d5ffe8c4dfd8c..c8c02ab0f3e09 100644
--- a/lld/ELF/ScriptLexer.cpp
+++ b/lld/ELF/ScriptLexer.cpp
@@ -272,15 +272,6 @@ StringRef ScriptLexer::peek() {
   return tok;
 }
 
-StringRef ScriptLexer::peek2() {
-  skip();
-  StringRef tok = next();
-  if (errorCount())
-    return "";
-  pos = pos - 2;
-  return tok;
-}
-
 bool ScriptLexer::consume(StringRef tok) {
   if (next() == tok)
     return true;
diff --git a/lld/ELF/ScriptLexer.h b/lld/ELF/ScriptLexer.h
index 7919e493fa28b..d5393818ed553 100644
--- a/lld/ELF/ScriptLexer.h
+++ b/lld/ELF/ScriptLexer.h
@@ -26,7 +26,6 @@ class ScriptLexer {
   bool atEOF();
   StringRef next();
   StringRef peek();
-  StringRef peek2();
   void skip();
   bool consume(StringRef tok);
   void expect(StringRef expect);
diff --git a/lld/ELF/ScriptParser.cpp b/lld/ELF/ScriptParser.cpp
index f20de5e2fb4fb..ce1b0e31d0523 100644
--- a/lld/ELF/ScriptParser.cpp
+++ b/lld/ELF/ScriptParser.cpp
@@ -92,7 +92,7 @@ class ScriptParser final : ScriptLexer {
   SymbolAssignment *readSymbolAssignment(StringRef name);
   ByteCommand *readByteCommand(StringRef tok);
   std::array<uint8_t, 4> readFill();
-  bool readSectionDirective(OutputSection *cmd, StringRef tok2);
+  bool readSectionDirective(OutputSection *cmd, StringRef tok);
   void readSectionAddressType(OutputSection *cmd);
   OutputDesc *readOverlaySectionDescription();
   OutputDesc *readOutputSectionDescription(StringRef outSec);
@@ -875,12 +875,11 @@ constexpr std::pair<const char *, unsigned> typeMap[] = {
 // "(TYPE=<value>)".
 // Tok1 and Tok2 are next 2 tokens peeked. See comment for
 // readSectionAddressType below.
-bool ScriptParser::readSectionDirective(OutputSection *cmd, StringRef tok2) {
-  if (tok2 != "NOLOAD" && tok2 != "COPY" && tok2 != "INFO" &&
-      tok2 != "OVERLAY" && tok2 != "TYPE")
+bool ScriptParser::readSectionDirective(OutputSection *cmd, StringRef tok) {
+  if (tok != "NOLOAD" && tok != "COPY" && tok != "INFO" && tok != "OVERLAY" &&
+      tok != "TYPE")
     return false;
 
-  expect("(");
   if (consume("NOLOAD")) {
     cmd->type = SHT_NOBITS;
     cmd->typeIsSet = true;
@@ -919,19 +918,22 @@ bool ScriptParser::readSectionDirective(OutputSection *cmd, StringRef tok2) {
 // https://sourceware.org/binutils/docs/ld/Output-Section-Address.html
 // https://sourceware.org/binutils/docs/ld/Output-Section-Type.html
 void ScriptParser::readSectionAddressType(OutputSection *cmd) {
-  if (peek() == "(") {
+  if (consume("(")) {
     // Temporarily set inExpr to support TYPE=<value> without spaces.
     SaveAndRestore saved(inExpr, true);
-    if (readSectionDirective(cmd, peek2()))
+    if (readSectionDirective(cmd, peek()))
       return;
+    cmd->addrExpr = readExpr();
+    expect(")");
+  } else {
+    cmd->addrExpr = readExpr();
   }
-  cmd->addrExpr = readExpr();
 
-  if (peek() == "(") {
+  if (consume("(")) {
     SaveAndRestore saved(inExpr, true);
-    StringRef tok2 = peek2();
-    if (!readSectionDirective(cmd, tok2))
-      setError("unknown section directive: " + tok2);
+    StringRef tok = peek();
+    if (!readSectionDirective(cmd, tok))
+      setError("unknown section directive: " + tok);
   }
 }
 

>From 3763da3467043e18c4bab55e875ca92ff219b886 Mon Sep 17 00:00:00 2001
From: Hongyu Chen <hongyuchy at google.com>
Date: Sat, 20 Jul 2024 23:20:46 +0000
Subject: [PATCH 2/2] [ELF] Update readSectionDirective function comments. NFC

---
 lld/ELF/ScriptParser.cpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/lld/ELF/ScriptParser.cpp b/lld/ELF/ScriptParser.cpp
index ce1b0e31d0523..49aa7e6374905 100644
--- a/lld/ELF/ScriptParser.cpp
+++ b/lld/ELF/ScriptParser.cpp
@@ -873,8 +873,6 @@ constexpr std::pair<const char *, unsigned> typeMap[] = {
 // Tries to read the special directive for an output section definition which
 // can be one of following: "(NOLOAD)", "(COPY)", "(INFO)", "(OVERLAY)", and
 // "(TYPE=<value>)".
-// Tok1 and Tok2 are next 2 tokens peeked. See comment for
-// readSectionAddressType below.
 bool ScriptParser::readSectionDirective(OutputSection *cmd, StringRef tok) {
   if (tok != "NOLOAD" && tok != "COPY" && tok != "INFO" && tok != "OVERLAY" &&
       tok != "TYPE")